Abstract
Effects of B content and heat treatment on properties of gas atomized powders with Ni-10mass%Cr-36mass%Mo-Xmass%B compositions (X=1.5∼4) were investigated. Examined powders were produced by gas atomization, followed by sieving under 150 μm. These powders were heat treated at various temperatures to investigate the effect of heat treatment temperature.
As a result, tetragonal M3B2, tetragonal M5B3 and orthorhombic M3B2 type complex borides were observed in examined powders before and after the heat treatment. Compositions and crystal structures of complex borides varied depending on B contents in examined powders, hereby compositions of Ni-based matrix phases also varied. Vickers hardness after the heat treatment at 1473 K increased with increasing B content.
